Fix where the build-on-all wasn't passing TOP_UPSTREAM variables

What does this MR do?

Fixes an issue where we weren't passing TOP_UPSTREAM variables to build on all OS. This causes issues when the build is triggered from the gitlab-foss or security projects, where we need to grab the assets from those projects.

This change updates the build-package-on-all-os-vars to extend from our base trigger vars which have this support.

Test Plan

We can confirm that one of the TOP_UPSTREAM variables is correct when we choose one that would be otherwise be different for different child pipelines.

You can find the variables in the build_facts/env_vars aftifacts file in the generate_facts job of an omnibus pipeline.

So for a MR pipeline like we have in this MR

1. Trigger the ee-package or ce-package pipeline
2. Go into the pipeline and trigger the build-on-all-os pipeline
3. Go into that child pipeline, and check the env_vars in the generate_facts job
4. The TOP_UPSTREAM_SOURCE_JOB variable should point at a generate_facts job in our very top level MR pipeline and not be either of the two child pipelines.

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• MR title and description are up to date, accurate, and descriptive.
• MR targeting the appropriate branch.
• Latest Merge Result pipeline is green.
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow.

For GitLab team members

If you don't have access to this, the reviewer should trigger these jobs for you during the review process.

• The manual Trigger:ee-package jobs have a green pipeline running against latest commit.
• If config/software or config/patches directories are changed, make sure the build-package-on-all-os job within the Trigger:ee-package downstream pipeline succeeded.
• If you are changing anything SSL related, then the Trigger:package:fips manual job within the Trigger:ee-package downstream pipeline must succeed.
• If CI configuration is changed, the branch must be pushed to dev.gitlab.org to confirm regular branch builds aren't broken. https://dev.gitlab.org/gitlab/omnibus-gitlab/-/pipelines/292009

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes.
• Documentation created/updated.
• Tests added.
• Integration tests added to GitLab QA.
• Equivalent MR/issue for the GitLab Chart opened.
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.